Aftertreatment module having replaceable catalyst housing

ABSTRACT

An aftertreatment module is disclosed for use with an engine. The aftertreatment module may have an inlet housing at least partially defining an inlet passage for exhaust, and at least one mixer disposed in the inlet passage. The aftertreatment module may also have an outlet housing at least partially defining an outlet passage for exhaust, and a catalyst housing removably connected between the inlet housing and the outlet housing. The aftertreatment module may further have a plurality of catalyst substrates configured to be mounted in the catalyst housing, to receive exhaust from the inlet passage in parallel, and to discharge exhaust to the outlet housing in parallel.

TECHNICAL FIELD

The present disclosure is directed to an aftertreatment module and, moreparticularly, to an aftertreatment module having a replaceable catalysthousing.

BACKGROUND

Internal combustion engines, including diesel engines, gasoline engines,gaseous fuel-powered engines, and other engines known in the art exhausta complex mixture of air pollutants. These air pollutants are composedof gaseous compounds including, among other things, the oxides ofnitrogen (NO_(X)). Due to increased awareness of the environment,exhaust emission standards have become more stringent, and the amount ofNO_(X) emitted to the atmosphere by an engine may be regulated dependingon the type of engine, size of engine, and/or class of engine.

In order to comply with the regulation of NO_(X), some enginemanufacturers have implemented a strategy called selective catalyticreduction (SCR). SCR is an exhaust treatment process where a reductant,most commonly urea ((NH₂)₂CO) or a water/urea solution, is selectivelyinjected into the exhaust gas stream of an engine and adsorbed onto adownstream substrate. The injected urea solution decomposes into ammonia(NH₃), which reacts with NO_(X) in the exhaust gas to form water (H₂O)and diatomic nitrogen (N₂).

In some applications, the substrate used for SCR purposes may need to bevery large to help ensure it has enough surface area or effective volumeto adsorb appropriate amounts of the ammonia required for sufficientreduction of NO_(X). These large substrates can be expensive and requiresignificant amounts of space within the engine's exhaust system. Inaddition, the substrate must be placed far enough downstream of theinjection location for the urea solution to have time to decompose intothe ammonia gas and to evenly distribute within the exhaust flow for theefficient reduction of NO_(X). This spacing may further increasepackaging difficulties of the exhaust system.

Exhaust backpressure caused by the use of the SCR substrate describedabove can be problematic in some situations. In particular, the SCRsubstrate can restrict exhaust flow to some extent and thereby cause anincrease in the pressure of exhaust exiting an engine. If this exhaustback pressure is too high, the breathing ability and subsequentperformance of the engine could be negatively impacted. Accordingly,measures should be taken to avoid overly restricting exhaust flow whenimplementing SCR.

An exemplary aftertreatment module is disclosed in U.S. Pat. No.8,747,788 of Baig et al. that issued on Jun. 10, 2014 (“the '788patent”). In particular, the '788 patent discloses an aftertreatmentmodule having a housing with an inlet and an outlet, and a catalyst bankseparating the inlet from the outlet. The catalyst bank has a facedisposed at an oblique angle relative to a flow direction through theinlet and the outlet. Passages having decreasing cross-sectional areasextend from the inlet to the catalyst bank, and from the catalyst bankto the outlet.

Although the aftertreatment module of the '788 patent may be functionalin many applications, it may still be less than optimal. In particular,the catalyst bank may wear out after a period of time, and the catalystbank may not be easily serviceable.

The aftertreatment module of the present disclosure addresses one ormore of the needs set forth above and/or other problems of the priorart.

SUMMARY

In one aspect, the present disclosure is directed to an aftertreatmentmodule. The aftertreatment module may include an inlet housing at leastpartially defining an inlet passage for exhaust, and at least one mixerdisposed in the inlet passage. The aftertreatment module may alsoinclude an outlet housing at least partially defining an outlet passagefor exhaust, and a catalyst housing removably connected between theinlet housing and the outlet housing. The aftertreatment module mayfurther include a plurality of catalyst substrates configured to bemounted in the catalyst housing, to receive exhaust from the inletpassage in parallel, and to discharge exhaust to the outlet housing inparallel.

In another aspect, the present disclosure is directed to anotheraftertreatment module. This aftertreatment module may include an inlethousing at least partially defining an inlet passage having a firstaxis, and a first mounting flange oriented at an oblique angle relativeto the first axis. The aftertreatment module may also include an outlethousing at least partially defining an outlet passage having a secondaxis, and a second mounting flange oriented at an oblique angle relativeto the second axis. The aftertreatment module may further include acatalyst housing removably connected between the first and secondmounting flanges.

In yet another aspect, the present disclosure is directed to anaftertreatment module for a vehicle having a mounting platformconfigured to be generally parallel with a ground surface supporting thevehicle. The aftertreatment module may include an inlet housing, anoutlet housing, and a catalyst housing removably connected between theinlet housing and the outlet housing. The aftertreatment module mayfurther include a mounting bracket having a bottom support configured toconnect a bottom of the outlet housing to the mounting platform, and aside support protruding from the bottom support at an oblique angle andconfigured to engage a side of the outlet housing and a side of thecatalyst housing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a pictorial illustration of an exemplary disclosed powersystem;

FIG. 2 is an exemplary mounting arrangement of two exemplary disclosedaftertreatment modules that may be used with the power system of FIG. 1;

FIG. 3 is an exploded view illustration of another exemplary disclosedaftertreatment module that may be utilized in conjunction with the powersystem of FIG. 1; and

FIG. 4 is a cross-sectional illustration of the aftertreatment module ofFIG. 3.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary power system 10. For the purposes ofthis disclosure, power system 10 is depicted and described as a mobilemachine, for example a haul truck, having one or more multi-cylinderinternal combustion engines (not shown). Each engine may be configuredto combust a mixture of air and fuel, for example diesel, gasoline, or agaseous fuel, and to generate a mechanical output. The mechanical outputfrom the engine(s) may be directed to propel the mobile machine.Alternatively, the engine(s) may embody the main or auxiliary powersource of a stationary power system 10, such as a pump, if desired.

Power system 10 may be equipped with one or more aftertreatment modules(“modules”) 12 having components that cooperate to promote theproduction of power and to simultaneously control the emission ofpollutants from the engine(s) to the atmosphere. In the embodiment ofFIG. 1, power system 10 includes a single module 12 mounted to platform14 that is configured to be generally parallel with a ground surface onwhich power system 10 is supported. In this embodiment, platform 14 islocated gravitationally above any associated engine(s), and ductwork(not shown) may connect module 12 to the engine(s). A mounting bracket(or system of brackets) 16 may be used to connect module 12 to platform14.

An exemplary mounting arrangement module 12 is shown in FIG. 1. In thisarrangement, mounting bracket 16 is configured to engage two primarysurfaces of a single module 12 and to hold module 12 at an orientationthat avoids interference with other features of power system 10. Inparticular, mounting bracket 16 may include a bottom support 16 a thatis configured to connect to a housing bottom or lower-most portion ofmodule 12, and a side support 16 b that is configured to connect tohousing side or upright portion of module 12. Side support 16 b mayprotrude from bottom support 16 a at an oblique angle, such that module12 is tilted forward (relative to a normal travel direction of powersystem 10) and away from a bed of power system 10. A clearance may bemaintained between module 12 and the bed of power system 10 duringoperation. Bottom and side supports 16 a, 16 b may be integrally formedas a single component through a casting or fabrication process. In someembodiment, multiple mounting brackets 16 (e.g., one at each end) may beused to secure module 12 to platform 14.

An alternative mounting arrangement is depicted in FIG. 2. In thisarrangement, two modules 12 are shown as being packaged together, tothereby accommodate an engine configuration having increased exhaustflow and/or pollutant concentration. In this arrangement, modules 12 maybe stacked together (e.g., side-by-side) and mounted in a verticalorientation at any suitable location onboard power system 10, forexample on top of a fuel tank (not shown). Four substantially identicalmounting brackets 16 (two on each side of modules 12, with one at eachend of the corresponding module 12) having only side supports 16 b maybe utilized in this embodiment. It is contemplated that any number ofmodules 12 could be packaged together at any location and/or in anyorientation onboard power system 10, as desired.

As shown in FIG. 3, each module 12 may be an assembly of components,which are removably connected to each other. For the purposes of thisdisclosure, the phrase “removably connected” may refer to a means ofconnection that does require a deformitive or destructive process (e.g.,cutting, ripping, grinding, bending, melting, etc.) to reverse. Module12 may include, among other things, an inlet housing 18, an outlethousing 20, and a catalyst housing 22 located between inlet and outlethousings 18, 20. One or more seals or gaskets 24 may be located betweenadjacent housings (e.g., between mounting flanges 25 of adjacenthousings), and a plurality of fasteners 26 may be used to removeablyconnect the housings together.

As can be seen in FIGS. 3 and 4, inlet and outlet housings 18, 20 mayeach have a height h₁, h₂, respectively, that varies in a lengthdirection, while catalyst housing 22 may have a height h₃ that remainssubstantially constant along its length. In particular, a cross-section(shown in FIG. 4) of inlet and outlet housings 18, 20 may be generallytriangular, while a cross-section of catalyst housing 22 may begenerally rectangular. The triangular shapes of inlet and outlethousings 18, 20 may be inverted both vertically and horizontally(relative to the perspective of FIGS. 3 and 4), such that an overallcross-section of module 12 may be generally rectangular. With thisconfiguration, mounting flanges 25 may be oriented at an oblique anglerelative to axes 28 and 30. Once catalyst housing 22 is assembledbetween flanges 25, catalyst housing 22 may be inclined relative to thetop, bottom, and sides of module 12.

In the embodiment shown in FIGS. 3 and 4, exhaust may flow into module12 in a first direction and flows out of module 12 in a second directionsubstantially orthogonal to the first direction. In particular, theentering flow of exhaust may be aligned with an axis 28 that extendsthrough a side of module 12, while the exiting flow of exhaust may bealigned with an axis 30 that extends through a bottom of module 12. Itis contemplated, however, that the entering and exiting flows of exhaustcould alternatively be aligned in the same or opposing directions (seeFIG. 2), if desired, in order to accommodate different engine/powersystem routing requirements.

Inlet housing 18 may at least partially define an inlet passage 32, anda distribution space 34 located below inlet passage 32 (i.e., locatedcloser to an open bottom of inlet housing 18). Exhaust may enter inletpassage 32 at one side of inlet housing 18, and travel the length ofinlet housing 18 to an opposing side. At the opposing side, the flow ofexhaust may reverse direction as it enters distribution space 34.

In the disclosed embodiment, inlet passage 32 is a cylindrical conduithaving a cross-sectional area that remains substantially constant alongits length. One or more reductant injectors 36 (e.g., two to fourinjectors spaced at various axial and/or annular locations) may bepositioned at an entrance to inlet passage 32, and one or more mixers 38(e.g., three mixers of different types and/or orientations) may bedisposed inside inlet passage 32 at locations downstream of injectors36. Mixers 38 may be configured to evenly mix injected reductant withexhaust as it enters module 12, and to inhibit the reductant fromimpinging and/or condensing on walls thereof. In the example of FIGS. 3and 4, injector(s) 36 are located and oriented to spray reductantdirectly into a portion of the most-upstream mixer 38. It should benoted, however, that other configurations and arrangements of injectors36 and mixers 38 may be possible.

Distribution space 34 may be designed to distribute exhaust receivedfrom inlet passage 32 substantially evenly across the open bottom ofinlet housing 18. In particular, distribution space 34 may have adecreasing cross-sectional area along a flow direction. This flow areamay decrease at a rate that results in a pressure along a length andwidth of distribution space 34 remaining about the same. In thedisclosed embodiment, a diffuser 40 (e.g., a perforated plate) may belocated at an intersection of inlet passage 32 and distribution space 34(e.g., at a location where the exhaust flow reverses direction).Diffuser 40 may function to deflect a majority of the exhaust flowtoward an opposing end of distribution space 34 where thecross-sectional area becomes smaller. A length and/or porosity ofdiffuser 40 may be tuned to provide a desired distribution of exhaustfor a particular application. In addition, in some applications, arestrictor 42 (e.g., a solid tab) may protrude from inlet passage 32downward into distribution space 34 at a downstream end of diffuser 40.The location, height, and/or width of restrictor 42 may be adjusted toprovide desired exhaust distribution characteristics.

Outlet housing 20 may at least partially define an outlet passage 44centered along length and width directions, and a collection space 46located above outlet passage 44 (i.e., located closer to an open top ofoutlet housing 20). Exhaust may enter collection space 46 along thelength of outlet housing 20, and travel inward toward outlet passage 44at the center of outlet housing 20.

In the disclosed embodiment, outlet passage 44 is a cylindrical conduithaving a cross-sectional area that remains substantially constant alongits length. A swirl end cap 48 may be positioned at an entrance tooutlet passage 44, and one or more sensor flutes 50 may be disposedinside outlet passage 44 at locations downstream of swirl end cap 48.Swirl end cap 48 may be a perforated plate having vanes at an outletside that are configured to generate swirl in the exhaust as the exhaustexits module 12. Swirl may help to improve a consistency of readingstaken by sensors (not shown) mounted within or otherwise connected toflutes 50.

Collection space 46 may be designed to collect exhaust from across theopen top of outlet housing 20, while maintaining a substantiallyconstant pressure and flow rate along its length. For this reason,collection space 46 may have a decreasing cross-sectional area along itslength. Specifically, at an axial position that generally correspondswith the entrance to distribution space 34 (i.e., where the flows andpressures are greater), the flow area inside collection space 46 may besmallest. And at an axial position that generally corresponds with theterminus of distribution space 34 (i.e., where the flows and pressuresare smaller), the flow area inside collection space 46 may be greatest.This flow area profile may encourage even exhaust flow through catalysthousing 22.

Catalyst housing 22 may be a generally four-walled structure having anopen top facing inlet housing 18 and an open bottom facing outlethousing 20. A tubular support 51 may be formed inside catalyst housing22 that is configured to house a plurality of catalyst substrates(“substrates”) 52. In particular, support 51 may include multiple tubes(e.g., six) arranged in parallel with each other relative to the flow ofexhaust passing through catalyst housing 22, each tube being configuredto house one or more (e.g., two) substrates 52 that are arranged inseries. Each of substrates 52 may be a Selective Catalytic Reduction(SCR) type of substrate 52, and by arranging multiple substrates 52within each tube, a distribution of exhaust across end faces of and aneffectiveness of substrates 52 may be improved. It should be noted,however, that in other embodiments, the substrates 52 housed within acommon tube could alternatively be different types of substrates. Forexample, the upstream substrate 52 could be a Diesel Oxidation Catalyst(DOC) substrate, while the downstream substrate 52 could be an SCRsubstrate. Other configurations may also be possible.

As an SCR type of substrate, each substrate 52 may be fabricated from orotherwise coated with a ceramic material such as titanium oxide; a basemetal oxide such as vanadium and tungsten; zeolites; and/or a preciousmetal. With this consist, decomposed reductant entrained within theexhaust flowing through mixers 38 and distribution space 34 may beadsorbed onto the surface and/or absorbed within of each substrate 52.The reductant may then react with NOx (NO and NO₂) in the exhaust gas toform water (H₂O) and diatomic nitrogen (N₂), which may be unregulatedsubstances.

As a DOC type of substrate, each substrate 52 may be fabricated from orotherwise coated with a precious metal such as palladium, platinum,vanadium, or a mixture thereof. With this composition, the substrates 52may catalyze a chemical reaction to alter the exhaust passing throughaftertreatment module 12. For example, substrates 52 may help to convertor otherwise reduce CO, NO, HC, and/or other constituents of the exhaustfrom the engine(s) into harmless substances such as CO₂, NO₂, and H₂O.In another embodiment, substrates 52 may alternatively or additionallyperform particulate trapping functions (i.e., substrates 52 may becatalyzed particulate traps), if desired.

Catalyst housing 22 may tilted in order to accommodate the triangularshapes of inlet and outlet housings 18, 20 (i.e., in order to form thegraduated flow areas that promote even exhaust flow through substrates52). In particular, substrates 52 may each have an upstream end facethat lies in a common plane and that is oriented at an oblique anglerelative to the flow direction through inlet passage 32 (i.e., relativeto axis 28), and a downstream end face that lies within a common planeand that is oriented at an oblique angle relative to a flow directionthrough outlet passage 44 (i.e., relative to axis 30).

INDUSTRIAL APPLICABILITY

The aftertreatment module of the present disclosure may be applicable toany power system configuration requiring exhaust constituentconditioning, where component packaging and serviceability are importantissues. The disclosed aftertreatment module may improve packaging byutilizing multiple small substrates and by efficiently using availableonboard space. The disclosed aftertreatment module may improveserviceability by providing for separate replacement of catalyst housing22. Operation of power system 10 will now be described.

Referring to FIGS. 3 and 4, the exhaust produced by the engine(s) ofpower system 10 may flow horizontally inward through inlet housing 18 ina first direction via inlet passage 32. As the exhaust flows throughinlet passage 32, reductant may be sprayed into the exhaust by injectors36 and mixed together with the exhaust by mixers 38. When thereductant-laden exhaust reaches the end of inlet passage 32, it may beredirected downward through about 180° to enter distribution space 34.Some of the exhaust may impinge diffuser 40 and some may pass throughdiffuser 40 to the substrate 52 located immediately below. The exhaustimpinging diffuser 40 may deflect away in a second direction generallyopposite to the first direction. The exhaust may then flow down thelength of distribution space 34 and be pushed downward through theremaining substrates 52 by narrowing of the cross-sectional area ofdistribution space 34.

As the exhaust flows through substrates 52, the reductant entrainedtherein may break down in NH₃ and be adsorbed and/or absorbed therein.This may facilitate a catalytic reaction within substrates 52 thatcoverts NO_(X) in the exhaust to harmless substances. The exhaust maythen pass out of substrates 52 into collection space 46, and beredirected inward toward outlet passage 44. The exhaust may pass throughswirl end cap 48, wherein the vanes thereof generate swirling of theexhaust to create a substantially homogenous exhaust mixture. Mixing maybe beneficial as the exhaust passing through each tube of substrates 52may have a slightly different composition. In order to obtain a reliableand consistent sensor reading at flutes 50, it may be necessary to mixthe different exhaust flows into a more homogeneous flow. The exhaustmay then exit outlet passage 44 in a direction substantially orthogonalto the first and second directions.

Catalyst housing 22, along with tubular support 51 and substrates 52,may be configured to be easily replaced (e.g., in the field or in theshop) as a single unit. In particular, after a period of time, theefficiency of substrates 52 may decrease. And in order for power system10 to remain compliant with government regulations, substrates 52 mayneed to be replaced. In a conventional aftertreatment module, when thisoccurs, the entire module is replaced with a completely new module. Thiscan be expensive and labor intensive. However, in the disclosedaftertreatment module, it may be possible to replace only catalysthousing 22.

To replace catalyst housing 22, fasteners 26 may be removed, and inletand outlet housings 18, 20 separated from catalyst housing 22. A new (orrefurbished) catalyst housing 22 may then be placed between flanges 25of the existing inlet and outlet housings 18, 20, and fasteners 26reinstalled. In some applications, gaskets 24 may also be replaced atthis time. One or more lifting eyes (not shown) may be associated withcatalyst housing 22 and connected, for example, to tubular support 51.The lifting eyes may be used to hoist catalyst housing 22 during removaland installation. This service may take little time and have a low costassociated therewith.

Aftertreatment module 12 may be configured for use in many differentapplications, even though some applications may require more exhausttreatment than other applications. In particular, catalyst housing 22may be configured to house substrates 52 having different lengths,wherein the lengths are selected to correspond with the particularapplication. For example, when aftertreatment module 12 is applied to apower system 10 having lower exhaust flow rates and/or pollutantconcentrations, shorter substrates 52 may be installed within tubularsupport 51 of catalyst housing 22. In contrast, when aftertreatment 12is applied to a power system 10 having higher exhaust flow rates and/orpollutant concentrations, longer substrates 52 may be installed withintubular support 51 of catalyst housing 22. Aftertreatment module 12 maydesigned such that an overall size and shape thereof does not changewhen being used with substrates of different lengths. In this way,commonality of parts between applications can be increased, which maylead to an entity requiring a smaller part count on hand. This mayprovide for a cost reduction in most situations. It is contemplated,however, that catalyst housings 22 having different heights may beinterchangeably used with the same inlet and outlet housings 18, 20, ifdesired.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the aftertreatment module ofthe present disclosure without departing from the scope of thedisclosure. Other embodiments will be apparent to those skilled in theart from consideration of the specification and practice of the moduledisclosed herein. It is intended that the specification and examples beconsidered as exemplary only, with a true scope of the disclosure beingindicated by the following claims and their equivalent.

What is claimed is:
 1. An aftertreatment module, comprising: an inlethousing at least partially defining an inlet passage for exhaust; atleast one mixer disposed in the inlet passage; an outlet housing atleast partially defining an outlet passage for exhaust; a catalysthousing removably connected between the inlet housing and the outlethousing; and a plurality of catalyst substrates configured to be mountedin the catalyst housing, to receive exhaust from the inlet passage inparallel, and to discharge exhaust to the outlet housing in parallel. 2.The aftertreatment module of claim 1, wherein the at least one mixerincludes a plurality of mixers disposed in series.
 3. The aftertreatmentmodule of claim 2, further including a reductant injector connected tothe inlet housing and configured to inject reductant into an upstreamone of the plurality of mixers.
 4. The aftertreatment module of claim 1,further including a diffuser located inside the inlet housing anddownstream of the at least one mixer.
 5. The aftertreatment module ofclaim 4, wherein the diffuser is disposed outside of the inlet passageand in an exhaust flow path leading to only an upstream one of theplurality of catalyst substrates.
 6. The aftertreatment module of claim1, wherein each of the plurality of catalyst substrates has an upstreamend face oriented at an oblique angle relative to exhaust flow throughthe inlet passage.
 7. The aftertreatment module of claim 6, wherein eachof the plurality of catalyst substrates has a downstream end faceoriented at an oblique angle relative to exhaust flow through the outletpassage.
 8. The aftertreatment module of claim 1, further including anoutlet swirl cap located at an entrance to the outlet passage.
 9. Theaftertreatment module of claim 8, further including a flute extendinginto the outlet passage and configured to provide a mounting locationfor an exhaust sensor.
 10. The aftertreatment module of claim 1, furtherincluding a gasket disposed between the catalyst housing and each of theinlet and outlet housings.
 11. The aftertreatment module of claim 10,further including a plurality of fasteners configured to removablyconnect the catalyst housing to each of the inlet and outlet housings.12. The aftertreatment module of claim 1, wherein the plurality ofcatalyst substrates includes: a first set of catalyst substrates havinga first length; and at least a second set of catalyst substrates havinga second length, wherein: only one of the first and the at least asecond sets of catalyst substrates are disposed inside the catalysthousing at a time; and the first and the at least a second sets ofcatalyst substrates are interchangeable without requiring a change tothe catalyst housing.
 13. The aftertreatment module of claim 1, wherein:a height of the inlet housing reduces along a length of the inlethousing; a height of the outlet housing reduces along a length of theoutlet housing; and a height of the catalyst housing remains about thesame along a length of the catalyst housing.
 14. The aftertreatmentmodule of claim 1, wherein: a cross-sectional shape of the inlet housingis triangular; a cross-sectional shape of the outlet housing istriangular; a cross-sectional shape of the catalyst housing isrectangular; and a cross-sectional shape of the aftertreatment module isrectangular.
 15. The aftertreatment module of claim 14, wherein theinlet and outlet passages are both generally cylindrical.
 16. Anaftertreatment module, comprising: an inlet housing at least partiallydefining an inlet passage having a first axis, and a first mountingflange oriented at an oblique angle relative to the first axis; anoutlet housing at least partially defining an outlet passage having asecond axis, and a second mounting flange oriented at an oblique anglerelative to the second axis; and a catalyst housing removably connectedbetween the first and second mounting flanges.
 17. The aftertreatmentmodule of claim 16, further including: a gasket disposed between thecatalyst housing and each of the first and second mounting flanges; anda plurality of fasteners configured to pass through the gaskets and thefirst and second mounting flanges and to removably engage the catalysthousing.
 18. The aftertreatment module of claim 16, wherein: a height ofthe inlet housing reduces along a length of the inlet housing; a heightof the outlet housing reduces along a length of the outlet housing; anda height of the catalyst housing remains the same along a length of thecatalyst housing.
 19. The aftertreatment module of claim 16, wherein: across-sectional shape of the inlet housing is triangular; across-sectional shape of the outlet housing is triangular; across-sectional shape of the catalyst housing is rectangular; and across-sectional shape of the aftertreatment module is rectangular. 20.An aftertreatment module for a vehicle having a mounting platformconfigured to be generally parallel with a ground surface supporting thevehicle, the aftertreatment module comprising: an inlet housing; anoutlet housing; a catalyst housing removably connected between the inlethousing and the outlet housing; and a mounting bracket having a bottomsupport configured to connect a bottom of the outlet housing to themounting platform, and a side support protruding from the bottom supportat an oblique angle and configured to engage a side of the outlethousing and a side of the catalyst housing.